At just 33 years old, Janelle Whitehead is a living example of the shortcomings of these detection methods.

"I can't believe I was diagnosed with breast cancer that had already spread to the lymph nodes," she said. "I did everything right -- got my mammogram every single year, went to my doctor regularly, and felt myself up in the shower. Why wasn't it found earlier?"

Clearly we need something better. Until the breast cancer cure arrives, we need more tools to help us detect all breast cancers as early as possible when they are most treatable.

A New Tool for Cancer Detection

The March 29 issue of the New England Journal of Medicine published a study that looked at the ability of magnetic resonance imaging (or MRI) to detect breast cancer. MRIs use magnetic fields to highlight different kinds of tissues, distinguishing normal from abnormal.

In this case, women who were already diagnosed with cancer in one breast were screened with MRI on the other breast. So, for example, a woman diagnosed with right-sided breast cancer in this study would be screened with an MRI to determine whether there was breast cancer in her left breast (see breastcancer.org for more).

It is already known that women diagnosed with one breast cancer are at higher risk of developing another breast cancer -- and these woman want early detection for ANY cancer diagnosed -- on both sides.

This study showed that in nearly 1,000 women diagnosed with breast cancer on one breast, an MRI scan was able to detect breast cancer in 3 percent (30 of 969) of women on the other breast that was missed by mammography and clinical examination.

But MRI is a supersensitive test that can lead to many false alarms. Of the 121 women who had an MRI scan "abnormality," 30 proved to have cancer -- that's about 25 percent. This means that about 75 percent of the women had to be told that the MRI "abnormality" was not cancer.

Thoroughness Counts

Upon any diagnosis of breast cancer, it's important to carefully evaluate both breasts.

There is a tendency for you and your doctor to focus only on the one breast that first caught your attention and, as a result, neglect to pay close attention to the other breast. But knowing what's happening in both breasts -- as well as around the whole body -- helps you determine the best treatment strategy, giving you your best shot at getting rid of the cancer and staying cancer-free. Early detection may also help you avoid some of the heavy duty treatments like chemotherapy.

When you finish your treatment, you want to know that you've done everything possible to get rid of the cancer -- and never see the darn thing again! The last thing you want to have happen after graduating from "Cancer Land" is to find out about a new breast cancer that could have been found earlier.

Also, the value of MRI is not just limited to the other breast. It also has an important role in evaluating the same breast that the main cancer is found in -- to see if there is more than one cancer in there or an incomplete removal of the first one.

This study, however, did not talk about the use of MRI to detect other cancers in the same breast.

A Costly (but Important) Precaution

Women might need to put up a fight to get their insurance companies to pay for an MRI scan. MRI is expensive, and some medical insurance carriers are reluctant to pay.

Women might need to put up a fight to get their MRI scan paid for. MRI is expensive and some medical insurance carriers are reluctant to pay.

The best way to get your insurance company to cover the cost is to:

1) Get your doctor to write a clear, strongly worded request that explains why you need it; and

2) Get approval for the test before it's done (rather than putting up a fight afterward).

The take-home message is that MRI scan is important in the careful evaluation of both breasts upon a diagnosis of breast cancer. MRI is an extra tool in addition to mammography, clinical examination and self-examination. MRI does not replace mammography.

You have to stand up for yourself. Ask for the tests that you need to protect your greatest gift: your life.

Dr. Marisa Weiss is president and founder of breastcancer.org. She is also director of breast radiation oncology at Lankenau Hospital in Philadelphia, Pa.